|Publication number||US7624203 B2|
|Application number||US 11/381,680|
|Publication date||Nov 24, 2009|
|Filing date||May 4, 2006|
|Priority date||May 4, 2006|
|Also published as||US20070260788|
|Publication number||11381680, 381680, US 7624203 B2, US 7624203B2, US-B2-7624203, US7624203 B2, US7624203B2|
|Inventors||Katherine T Blinick, Yutaka Kawai, Gregg S Lucas, Robert E Medlin, Kenneth R Schneebeli, Michael Stamps|
|Original Assignee||International Business Machines Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (12), Referenced by (7), Classifications (5), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates generally to high speed serial cable interfaces and, in particular to tuning circuitry according to the length of a cable connected to such an interface.
Fibre-channel, arbitrated-loop (FC-AL) storage systems generally require external FC cabling to interconnect multiple storage enclosures together. Such cabling requires different cable lengths depending on how close or far the enclosures are located with respect to each other. As serial interfaces operate at higher and higher speeds (e.g. 3 Gb/s, 6 Gb/s 10 Gb/s), it is important that high speed signal tuning be performed when such high speed signals are routed through cables in order to improve signal transmission. Given the practical requirement for different cable lengths, it becomes important to selectively tune the high speed signal characteristics as a function of the cable length. Thus, it is common practice to amplify signals that traverse long cables and less-amplify signals that traverse shorter cables. In order to determine the signal amplification (e.g. pre-emphasis or de-emphasis), the cable length must be known.
In FC-AL cabled storage systems a device called a small form factor pluggable (SFP) device is used, either as a discrete component between the cable and the FC-AL device or integrated within the cable assembly.
Similar issues occur with serial attached SCSI (SAS) storage systems, However, the SAS external cable definitions do not provide any sideband signals for mini-SAS connectors (illustrated in
According to the present invention, the presence of a cable connected to a logic card is detected. The cable includes a non-volatile memory storing cable VPD. Rather than connecting the memory to the logic card with a dedicated line, a selected ground line is used. The selected line is disconnected from ground when the presence of a cable is detected and the cable VPD is read over the selected line to the logic card. The selected line is reconnected to ground and the connected cable is tuned in response to the cable VPD. A switching device, such as a transistor device, may be used to disconnect/reconnect the selected line from/to ground. A management controller may be used to detect the presence of a cable and to activate/deactivate the switching device. It may also be used to read the cable VPD information.
In normal operation, the management controller 654 causes the switching device 652 to be in a first state whereby the memory line 612 is coupled to ground. When a FET is used as the switching device 652, the management controller 654 activates the FET through the gate, causing a current to flow between the drain and source, effectively grounding the memory line 612. When the storage system is powered on, the management controller 654 interrogates all cable interfaces, such as the one illustrated in
It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions and a variety of forms and that the present invention applies regardless of the particular type of storage media actually used to carry out the distribution. Examples of computer readable storage media include recordable-type media such as a floppy disk, a hard disk drive, a RAM, and CD-ROMs.
The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. Moreover, although described above with respect to methods and systems, the need in the art may also be met with a computer program product containing instructions for accessing cable vital product data.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4311986 *||Sep 13, 1978||Jan 19, 1982||The Bendix Corporation||Single line multiplexing system for sensors and actuators|
|US5436593 *||Apr 28, 1994||Jul 25, 1995||Fiori, Jr.; David||Signal conditioning apparatus|
|US5664952||Sep 3, 1996||Sep 9, 1997||University Of Washington||Multichannel transmission line connector assembly|
|US5745795||Nov 4, 1996||Apr 28, 1998||Dell Usa, L.P.||SCSI connector and Y cable configuration which selectively provides single or dual SCSI channels on a single standard SCSI connector|
|US5768627||Dec 15, 1995||Jun 16, 1998||On Spec Electronic, Inc.||External parallel-port device using a timer to measure and adjust data transfer rate|
|US5995633||Dec 27, 1996||Nov 30, 1999||Apple Computer, Inc.||System and method for multiplexing control signals over data signal conductors|
|US6237048 *||Sep 8, 1998||May 22, 2001||International Business Machines Corporation||Adapter card with vendor unique differentiation and customization using PCI sideband signals|
|US6313868 *||Apr 20, 1999||Nov 6, 2001||Linvatec Corporation||Remote CCD video camera with non-volatile digital memory|
|US6576833 *||Apr 12, 2001||Jun 10, 2003||Cisco Technology, Inc.||Cable detect and EMI reduction apparatus and method|
|US6587062||Mar 25, 2002||Jul 1, 2003||Texas Instruments Incorporated||Flexible interface circuit and method for delta sigma A/D converters|
|US20040025089 *||Jul 30, 2002||Feb 5, 2004||Haswarey Asif H.||Enhanced VPD (Vital Product Data) structure|
|US20060025018 *||Jul 12, 2005||Feb 2, 2006||Finisar Corporation||First protocol to second protocol adapter|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US8112568 *||Jul 19, 2007||Feb 7, 2012||Netapp, Inc.||Cable presence detection system|
|US8655182 *||Feb 17, 2012||Feb 18, 2014||Sumitomo Electric Industries, Ltd.||Optical transceiver implemented with I2C busses arbitrated by selector|
|US8995147 *||Jun 13, 2012||Mar 31, 2015||Zhongshan Innocloud Intellectual Property Services Co., Ltd.||Connection assembly and electronic device|
|US9088119||Jan 20, 2013||Jul 21, 2015||Lenovo Enterprise Solutions (Singapore) Pte. Ltd.||Cable assembly|
|US9377585||Jun 16, 2015||Jun 28, 2016||Lenovo Enterprise Solutions (Singapore) Pte. Ltd.||Cable assembly|
|US20120213526 *||Feb 17, 2012||Aug 23, 2012||Sumitomo Electric Industries, Ltd.||Optical transceiver implemented with i2c busses arbitrated by selector|
|US20130203270 *||Jun 13, 2012||Aug 8, 2013||Hon Hai Precision Industry Co., Ltd.||Connection assembly and electronic device|
|U.S. Classification||710/16, 398/192|
|May 5, 2006||AS||Assignment|
Owner name: INTERNATIONAL BUSINESS MACHINES (IBM) CORPORATION,
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BLINICK, KATHERINE T.;LUCAS, GREGG S.;KAWAI, YUTAKA;AND OTHERS;REEL/FRAME:017576/0147;SIGNING DATES FROM 20060424 TO 20060502
|Jul 5, 2013||REMI||Maintenance fee reminder mailed|
|Nov 24, 2013||LAPS||Lapse for failure to pay maintenance fees|
|Jan 14, 2014||FP||Expired due to failure to pay maintenance fee|
Effective date: 20131124